Plasma Surface treatment as an effective method for improving material surface performance is widely applied to the fields of aerospace, automotive manufacturing, machinery, heavy industry, hardware tool manufacturing, etc. Plasma polymerized coating is an important surface treatment method. In the process of plasma polymerized coating, process gas and gaseous organic monomer shall be introduced into a vacuum chamber; plasma processing is performed on an organic gaseous monomer through discharge to produce all kinds of reactive species; and an addition reaction is conducted between the reactive species or between the reactive species and the monomer to form a polymer. Because the polymer coating is electrically insulated generally, a high-frequency discharge source must be used usually to produce plasma. To increase production efficiency and reduce the cost, the existing plasma polymerized coating device increases the area of the discharge source as much as possible to simultaneously treat more base materials. But the high-frequency discharge source with large area has large power threshold, generates plasma with high energy and high density, and is easy to excessively destroy a chemical monomer structure and cause bad quality of the formed polymer coating. In addition, because the high-frequency discharge source with large area has a standing wave effect, the generated plasma is uneven in spatial distribution so that the quality of products under batch treatment has bad uniformity.
Theoretically, the above problem can be solved by replacing a single high-frequency discharge source with large area and high power by combining a plurality of high-frequency discharge sources with small area and low power. However, in fact, because different high-frequency discharge sources are difficult to realize completely consistent phases and have mutual crosstalk, the high-frequency discharge sources are instable in operation and may burn out power supplies in severe cases. To reduce the crosstalk among the high-frequency discharge sources, the distance among the high-frequency discharge sources must be increased, while the generated plasmas may be uneven in spatial distribution if the distance among the high-frequency discharge sources is increased.